Certain 1,3-dihydropyridine derivatives (substituted in various ways) have pharmacologically-useful properties. European Patent Application Nos. 88,903, 94,159, and 106,276 provide examples. Surprisingly, it has now been found that new compounds (hereinafter described in more detail) which, in contrast to prior art compounds, carry a piperidine ring (which is disubstituted in the 4-position) have particularly interesting pharmacological properties by which they differ advantageously from their noted prior art counterparts.